Had a similar headache getting my Pylontech stack to talk properly to the inverter last year. The RS485 comms cable is usually the culprit — Pylontech's pinout isn't always what you'd expect and there's a fair bit of misinformation floating around on the generic wiring diagrams.
Few things worth checking:
- Make sure you're using the BMS port on the master US2000c, not the console port (easy mistake, they look identical)
- The Growatt needs to be set to LiB battery type and the BMS protocol set to Pylontech specifically — some firmware versions call it something slightly different
- Double-check your RS485 cable is a proper twisted pair, not just any old cat5 lying around
Also worth downloading the latest Growatt SPF firmware if you haven't already — there were some known comms bugs in earlier versions that caused the BMS handshake to fail silently. Your inverter would just sit there looking confused, which is exactly as annoying as it sounds. 😄
What firmware version are you currently running on both the inverter and the batteries? The Pylontech BMS firmware can be updated too, though it's a bit faffy to do.
Anyone else here running this particular combo? Would be good to get a few data points — I'm running Victron kit myself so can't speak from direct SPF experience, but the Pylontech side of things I know reasonably well.
